As of 1970, approximately 3.4 million abdominal series were performed each year in the United States at a total cost (1979 prices) of $225 million. The average abdominal series consists of at least two films, each of which is associated with a skin entrance dose of 670 mr and gonadal doses of 97 mr in men and 221 mr in women. This study will determine which individual or combination of clinical symptoms, signs, and laboratory data have high predictive value for the presence of abnormal findings on the abdominal series, as well as the degree to which these findings actually influence patient care. To obtain a sufficient sample, all patients who are referred for abdominal series at three hospitals (University, Veterans Administration, and General) during a nine-month period (9,000 patients) will be included. Referring physicians will fill out a computerized form detailing patient clinical symptoms, signs and laboratory data. The radiologists reading the abdominal series will fill out similar forms for radiographic findings. For all abnormal abdominal series, the referring physician will be contacted by telephone to determine whether the radiographic finding was pertinent to the clinical problem and in any way affected patient care. A computer analysis will determine the predictive value of specific clinical signs, symptoms, and laboratory data being associated with abnormal abdominal series and the extent to which these radiographic findings influenced patient management. In this way the investigators hope to establish a set of clinical findings that are associated with such a low likelihood of abnormal abdominal series that the elimination of the abdominal series on patients with these clinical findings would permit a significant savings in health care costs and radiation exposure without having a detrimental impact on patient care.